Star filters are primarily effective on point light sources. They are not ideal for use with linear light sources, such as neon lamps, or flat light sources, like screens from devices.
The cross-star effect produced by star filters can vary depending on the intensity of the light source or your distance from it. To ensure the desired effect, it's important to preview the light output through your camera’s viewfinder or monitor.
Additionally, star filters (such as the STAR 4) with a rotating frame allow you to adjust the cross angle by simply rotating the filter from a straight (+) to a slightly tilted (x) position. As with light output, you should confirm the angle through your viewfinder or monitor before capturing your shot.
For best results with star filters, use a focal length of 50mm or longer and shoot at nearly maximum aperture. Using a wide-angle lens or a very closed aperture may cause the light rays to appear fragmented in the final image.
